Techno-economic evaluations of post-combustion CO2 capture from sub- and super-critical circulated fluidised bed combustion (CFBC) power plants

The heat and power generation sector is facing fundamental changes for transition to a low carbon scenario due to significant environmental constraints. This paper is evaluating from techno-economic point of view the integration of post-combustion CO2 capture technologies into coal-based CFBC power plants operated in sub- and super-critical steam conditions. Two post-combustion CO2 capture technologies were assessed: a chemical gas-liquid absorption using alkanolamines (Methyl-DiEthanol-Amine - MDEA) and a gas-solid adsorption using calcium-based sorbent (Calcium Looping - CaL). The analysis evaluates how chemical gas-liquid absorption/gas-solid adsorption influence the techno-economic performances of CFBC power plants. As benchmark cases used to quantify the energy and cost penalties for CO2 capture, the correspondent sub- and super-critical CFBC plants without CO2 capture were considered. As the results show, the CaL concepts exhibits better net electrical efficiency (35% vs. 32%), higher carbon capture rate (97% vs. 90%) and improved economic indicators (e.g. 1860 vs. 2552 €/kW net power as specific capital investment, 34 vs. 41.6 €/MWh as O&M costs, 66 vs. 84 €/MWh as cost of electricity) compared to the MDEA cases (all these values being reported for the super-critical CFBC designs).